In some communication systems, such as Global System for Mobile Communications (GSM), Wideband Code Division Multiple Access Wireless (WCDMA), Code Division Multiple Addressing (CDMA), Worldwide Interoperability for Microwave Access (WiMAX), CDMA2000, TD-SCDMA, Long Term Evolution (LTE), WLAN/WiFi and so on, in order to improve communication quality, a kind of home network technology is exploited.
As shown in FIG. 1, a schematic diagram illustrating a structure of a UMTS in the prior art is illustrated. Universal Mobile Telecommunication System (UMTS) adopting a similar structure as the second generation mobile telecommunication is a third generation mobile telecommunication system adopting WCDMA air interface technology. The UMTS is usually called WCDMA telecommunication system.
The UMTS system comprises a Radio Access Network (RAN) and a Core Network (CN). Here, the Radio Access Network is used to process all functions related with Radio, while the CN processes all voice calling and data connection in the UMTS system, and realizes exchange and rout functions with External Network. The CN is logically divided into a Circuit Switched Domain (CS) and a Packet Switched Domain (PS).
The Core Network (CN) comprises various network cells, such as a MSC/VLR, a Serving GPRS Support Node (SGSN), a HLR, a Gateway Mobile-services Switching Centre (GMSC), a Gateway GPRS Support Node (GGSN) and so on. The External Network can be connected through the GMSC or the GGSN. For example, a Public Land Mobile Network (PLMN), a Public Switched Telephone Network (PSTN), an Integrated Services Digital Network (ISDN) and so on can be connected through the GMSC, and Internet can be connected through the GGSN.
The interface between a User Equipment (UE) and a UTRAN is Uu. A NodeB and a Radio Network Controller (RNC) can be connected with each other through an Iub interface, and RNCs are connected with each other through an Iur interface. The interfaces between the UTRAN and the CN are all called Iu interface, which comprises an Iu-CS interface and an Iu-PS interface.
With the development of mobile communication technology, the demands of users present diversification. In order to satisfy the diversified demands of users, home coverage NodeB, corporation level inner coverage NodeB and other private networks emerge as the times require. For example, Home NodeB (HNB) that is also called femtocell base station, femtocell, or AP (Action Point) turns into the most potential low-cost access technology.
As shown in FIG. 2, a schematic diagram illustrating a structure of the Home NodeB system in the prior art is illustrated. The system comprises at least one Home NodeB, a HNB Management System (HMS) and a Home NodeB Gateway (HNB-GW). Here, the HNB provides the Uu interface to UEs, while the HNB and the HNB-GW are connected with each other through the Iuh interface, and the HNB-GW and the CN are connected with each other through the Iu interface (including the Iu-CS and the Iu-PS).
The HNB-GW is equivalent to the CN for the HNB, and is equivalent to the RNC for the CN. UEs are accessed to the network through the HNB and the HNB-GW. In this case, the HNB realizes the functions of the NodeB and that of the RNC, the HNB-GW provides a HNB authentication and a control plane convergence and other functions, while the HMS mainly provides HNB related data configuration and other functions.
As a Home NodeB, the HNB, compared to traditional macro NodeBs, has the following characteristics: small coverage area, limited amount of carried users, large amount, dense deployment, multi-layer overlapping coverage, devices controlled by HNB users other than operators, HNB frequency band that may be different frequency deployed with Legacy network, low transmit power. The HNB may configure adjacent cells automatically through uplink detection, while it is hard to configure adjacent cell list in the prior art.
The application scenes of HNB are quite widely, such as home, corporation, public areas, etc. Different scenes have different demands on the HNB. For example, for the home usage, the coverage area of the HNB is small hence the number of users is small, while for the corporation usage, compared to the home usage, the coverage area of the HNB is relatively lager, and the number of user is obviously increased since users of the corporation are more concentrated.
In the macro network, UTRAN Radio Network Temporary Identity (U-RNTI, UTRAN) is used for identifying UE uniquely, and consists of two parts:U-RNTI(32 bit)=SRNC identity+S-RNTI.
Here, the SRNC identity is an identity of RNC, identifying one RNC uniquely in one Public Land Mobile Network (PLMN). While, the Serving-Radio Network Temporary Identifier (S-RNTI) is allocated by a Serving RNC (SRNC) and identifies one UE uniquely under one RNC. Generally speaking, the length of U-RNTI is 32 bits, the length of SRNC identity is 12 bits, and the length of S-RNTI is 20 bits. However, sometimes, an expansion is made to the SRNC identity whose length can reach to the maximum of 12 bits, while in this case, the length of the S-RNTI is 16 bits. In the UMTS macro network, the U-RNTI is allocated by a RNC entity to a UE with RRC connection. One new U-RNTI is allocated to the UE, when the UE sets up the RRC connection, or when the UE performs cell updating, or when the process of Serving Radio Network Subsystem (SUNS) relocation or other situation occurs.
However, for the HNB network, the RRC connection of UE terminates in the HNB. The HNB integrates functions of the NodeB and that of the RNC in the macro network, while the HNB-GW provides the function of control plane convergence. In the access network, the structure of the HNB network is evidently different from that of the macro network. In the HNB network, different methods of allocating U-RNTIs can be completed by any one or combination of the HNB and the HNB-GW. In this case, on the Iu interface of the HNB network, a RNC-ID is used for identifying HNB-GW uniquely in the Core Network, wherein the RNC-ID may be transferred to the HNB connected with the HNB-GW during a register process of the HNB. Therefore, when U-RNTI allocation is performed, the RNC-ID of HNB-GW may be used as the SRNC identity.
Therefore, in the HNB network, realizing of the U-RNTI may be as follows:U-RNTI=RNC-ID+S-RNTI.
However, since multiple HNBs can be connected to one HNB-GW, uniqueness of S-RNTI needs to be guaranteed when U-RNTIs are allocated to these HNBs.
In the conventional art, the HNB and HNB-GW complete the allocation of U-RNTIs together, which mainly shows as follows:
After initialing a calling, a UE sets up Radio Resource Control (RRC) connection with a HNB, and the HNB allocates randomly, in the Radio Resource Control Connection Setup (RRC Connection Setup) message, one U-RNTI to the UE. The UE initiates initial direct transfer, and the HNB transfers the U-RNTI allocated randomly by the HNB to the HNB-GW through RANAP User Adaption (RUA) CONNECT message, namely that the RUA CONNECT message transferred to the HNB-GW carries the randomly-allocated U-RNTI. The HNB-GW checks the allocated U-RNTI. If there is no conflict, the HNB-GW stores the U-RNTI and performs the normal process continuously. If a conflict is found, the HNB-GW reallocates one U-RNTI without conflict to the HNB. The HNB reallocates the U-RNTI to the UE, and notices the HNB-GW that the reallocation process has been completed.
In the conventional art, the HNB-GW needs to manage allocation operation of each U-RNTI, and further needs to store each allocated U-RNTI. Simultaneously, the HNB-GW further needs to traverse each stored U-RNTI to check whether a conflict occurs after the HNB allocates one new U-RNTI each time, which increases the implementation complexity of the HNB-GW and brings some time delay.